Claudia-Liza Armah spoke with veterans Ben Thompson and Paul McEwan, who found themselves struggling with alcohol dependency and homelessness once they left the armed forces.
Mr Thompson served in the Royal Logistic Corps for 16 years. Mr McEwan served in the Royal Marines for 13 years.
Both describe the strange, hard period when they had to adjust to civilian life.
Mr Thompson was rejected for council housing because his 16 years of service meant he been out of the country too long to qualify. Both he and Mr McEwan joined the armed forces as young men.
This meant when they left, they had very little experience of civilian life. Mr Thompson described facing "all the red tape I didn't understand”.
When he left the Royal Marines, Mr McEwan also left all his friends behind, meaning he had no support network to help him adjust to his new life, and no-one to give him any advice.
Alone, he developed a dependency on alcohol.
He describes how a hospital put him in touch with Veterans Aid after he was admitted following an alcohol-induced seizure. He has had over 20 seizures because of his alcoholism.
Mr Thompson also struggled with his drinking said: "I wasn't connecting with society.
"I knew my drinking was out of control."
He described how hitting rock bottom is different for everyone and how Veterans Aid helped him as he scrounged cigarette butts from Liverpool Street station, trying to give himself something to smoke.
The two veterans describe the help the charity have given them: taking them from the streets into homes, jobs, sobriety - and purpose.
Mr Thompson said: "Veterans Aid gave me a second chance at life."
Veterans Aid is one of two charities being supported by the Evening Standard,Independent and i Christmas appeal.
The charity last year provided more than 21,000 nights of accommodation for veterans in need.
The campaign will also be supporting ABF The Soldiers Charity.